The RS 6 Avant sits above the A6 and S6, with a 4.0-liter twin-turbo V8 rated at 592 horsepower and quattro all-wheel drive. Its body runs 40 mm wider on each side, with flared arches. Standard wheels are 21 inches. The one we have is a 2022 RS 6 Avant in Merlin Purple, with an automatic gearbox.